The present invention relates generally to the art of fluid sprinkling and more particularly to the art of snow making and an improved method and apparatus for artificially making large volumes of high quality snow suitable for skiing.
The present invention pertains to improvements over my invention disclosed in U.S. Pat. No. 5,004,151, issued Apr. 2, 1991. A suitable discussion providing a major portion of the prior art background of the present invention is presented in this patent and also in my U.S. Pat. No. 3,822,825, issued Jul. 9, 1974 and my U.S. Pat. No. 3,952,949, issued Apr. 27, 1976. Accordingly, the background provided in these patents is incorporated herein by reference.
Generally, my former inventions for artificially producing snow consist of a method and apparatus for making snow through the use of snow towers wherein water is supplied under pressure to a point of discharge well above ground level and adjacent the top end of the tower where it is discharged through a nozzle into the ambient freezing atmosphere in the form of a spray. The spray is preferably a high velocity spray of discrete water particles, sometimes referred to as a fine water spray produced by nozzles which are generally referred to as V-jet nozzles.
Air is supplied independently under pressure to a second point of discharge at the top of the snow tower and there discharged through an orifice to form a jet stream which is directed into the aforesaid water spray thereby forming a plume of atomized or nucleated water. This atomized water forms seed crystals in the freezing atmosphere, and through the dwell time of the long fall from the top of tower to the ground, forms snow. My prior methods and apparatus for making snow provide excellent quality snow in reasonable quantities and at a reasonable cost. However, it is my continuing objective and the objective of the industry to provide evermore economic and quality snow making towers which will make excellent quality snow with greater efficiency, at larger quantities and at a lower cost.
My U.S. Pat. No. 5,004,151 discloses the use of multiple water spray nozzles in a vertical array and further discloses that the secondary water spray nozzles may be changed so that some of the nozzles discharge more water than other nozzles and discharge the water at desired nucleated consistencies in order to achieve the most efficient and effective results. However, it is only as a result of this present invention that I have discovered the best and the most unique and efficient arrangement for providing selected different discharge rates for the water spray nozzles in order to achieve the most efficient and affective results. My new invention is thus described hereinafter.
In the method and apparatus of the present invention, a snow making tower is provided which is comprised of the typical air and water nozzle combination snow tower with the additional teachings of my present invention.
The typical snow tower, as taught by my prior art patents, is comprised of an elongated tower conduit combination, including an elongated air conduit extending within an elongated water conduit and provided with a ground support mount. Air and first water discharge nozzles are respectively provided adjacent the upper ends of these conduits and positioned for producing a plume of atomized water from external interacting air and water discharged under pressure from the air and first water discharge nozzles to produce snow in subfreezing ambient conditions. Couplings are also provided for connecting air and water under pressure respectively to the lower ends of these air and water conduits. At least two and usually three, additional water discharge nozzles are positioned below this first water nozzle and connected to the water conduit for providing additional water sprays and these additional water sprays are directed whereby at least portions thereof will intermix with the plume as it falls towards the ground.
The improvement resides in that these additional water nozzles, which are spaced below the first water nozzle in a vertical sequence, are dimensioned for discharging water respectively at a higher rate than each proceeding higher nozzle.
Also, there will usually be provided at the top of the tower three vertical adjacent sets or banks of these nozzles, each set including an air nozzle and first water discharged nozzle with the two, and preferably three, additional water discharge nozzles positioned respectively therebelow. Each vertical array nozzle set is positioned on opposite sides of the first set at a 60xc2x0 horizontal spacing whereby three plumes are created and spaced horizontally at 60xc2x0 from each other.
An example of the nozzle selection for the snow making tower of the present invention is that each of the air discharge nozzles is comprised of a {fraction (1/16)}xe2x80x3 diameter discharge hole as opposed to the conventional xe2x85x9xe2x80x3 diameter hole and the first water nozzle is selected to have a flow rate of 2 gpm and the additional water nozzles are dimensioned to provide approximate rates of flow which are 2 gpm respectively more than the preceding higher water nozzle. As the ambient temperature increases and the water discharge must be therefore decreased, the additional water nozzles may be closed by selectively plugging these lower water nozzles, typically from the lower most nozzle sequentially to the upper most additional water nozzle, as ambient temperatures increase from below freezing toward the freezing level.
All of the water nozzles are typically angled at approximately 45xc2x0 relative to vertical or horizontal. The air nozzles are preferably of the venturi type which I have previously disclosed and described in the prior art. These air nozzles provide greater thrust on discharge.
As a result of the nozzle arrangement of the present invention, approximately ⅓ the amount of air is used as compared to my prior art snow making towers. My towers formally required 50 cfm of air and an output of 50 gpm of water at a temperature of 26xc2x0 F. At the same temperature conditions the tower of my present invention requires only approximately 20 to 22 cfm of air (7 cfm per air nozzle) at 60 gpm of water (total for all water nozzles), and the tower is exceptionally light weight.
Also, the water nozzles of the present invention run at lower rates thereby providing a finer spray and as the subfreezing ambient temperatures increase, more of the lower additional water nozzles may be utilized.
With the snow making tower of the present invention the tower is operating utilizing approximately xc2xd the amount of water previously required and utilizing approximately xc2xc of the air previously required, yet making the same quantities of snow. The snow is much finer and very light due to the use of small nozzles which create a finer spray.
As the nozzle discharge rates increase for the additional water nozzles, the water particles become larger and their throw becomes longer and this assists the additional water sprays to interact better with the falling atomized plume.